Fabrication of eco-friendly calcium crosslinked alginate electrospun nanofibres for rapid and efficient removal of Cu(II)

Abstract

The preparation of low-cost adsorbents using naturally available biomaterials to realize the efficient removal of Cu(II) is urgently needed. Herein, low-cost and recyclable calcium crosslinked alginate electrospun nanofibres (SA-Ca) were prepared using low-cost materials via a low-energy-consumption process. The prepared SA-Ca possesses a porous network structure, and its average diameter, specific surface area, and tensile strength are approximately 129.6 nm, 3.409 m2 g−1, and 2.73MPa, respectively. The maximum adsorption capacity of SA-Ca for Cu(II) in aqueous solution is 285.5 mg g−1, and the adsorption can be completed in 0.5 h. The adsorption kinetics were well described by the general-order kinetic model, and the adsorption isotherm fitted to the Liu model. The study of the adsorption mechanism suggested that electrostatic attraction, ion exchange, and complexation cooperated to exert effects. More important, SA-Ca can be regenerated using CaCl2/HCl solutions based on the ion-exchange mechanism without destroying the morphology of the nanofibres. Furthermore, a low concentration of Cu(II) (10 mg L−1) and other heavy metal ions [Pb(II) and Cd(II), each 10 mg L−1] were successfully removed from water, demonstrating that economical biocarbohydrate polymer-based nanofibres have great application prospects in the removal of heavy metal ions.